Sauron

Further, knowing or suspecting that your messages could theoretically be accessed by snapchat is not the same as knowing for a fact that they will be, or that there are automatic filters that will alert international police based on keywords like "taliban". We're not even sure that's what happened considering it could also have been reported by someone in the chat (in which case, I'd say the person to be charged with causing a false alarm would be the one who reported it, knowing perfectly well it was a joke) - this may even be more likely considering they knew not just the name of the person but also which plane they would have been boarding, although I'm sure snapchat also collects location data. I also question the legitimacy of just mass screening people's private conversation without a warrant or prior suspicion, if that's what actually happened, and using it as evidence in a trial. I'm almost certain this is illegal where I live (we even had a big case about the police not being allowed to use intercepted phone calls as evidence, and that was with significant evidence of wrongdoing). You can't even be certain that the person using a given account or phone number is who they claim to be.

It says and/or... https://www.reuters.com/technology/apple-allow-downloads-outside-app-store-eu-with-new-fees-2024-01-25/ I don't think this complies with the spirit of the law. You can't allow sideload but only if they pay you for it. This is already stupidly expensive but if this logic holds what's to stop them from charging you a billion for each sideload, effectively making it impossible? It doesn't work for open source apps that can't afford to pay these fees. Also a huge reason for sideloading is specifically to avoid Apple gatekeeping what you can or can't install on your device... it doesn't work if your app still has to be approved by them before you can install it. With this they can still decide which apps or app stores are even allowed on the device, regardless of the fee. I don't give Tim Sweeney too much credit but at least he has some legal experience on the matter...:

I agree, I'm saying that somehow I doubt this would have caused anything to happen if he had written "gonna blow up the train lmao" at a train station.

I don't think you can in C. Once the value has overflowed or underflowed its impossible to tell the current value is not correct. The only way to prevent overflows is to check for them before running the operation or assignment. Instead of this: unsigned int a; //some code here a -= 1; do this: unsigned int a; //some code here if (a > 0) { a -= 1; } C will not prevent you from writing bad code. Some languages, like Rust, have built-in utilities to avoid this problem: https://doc.rust-lang.org/std/primitive.i32.html#method.checked_add but fundamentally the logic is the same; check that the operation would not cause an overflow before running it.

Do you not see the difference between a bomb threat being directly sent to a school or a bag being left unattended, and someone writing a joke in a text chat they assume to be private? Who's intercepting your snapchat while you board a train? At the very least, if you're going to prosecute people for causing false alarms you need to let them know what the triggers are. Personally I think intercepting everyone's private conversations, without any evidence at all of them being dangerous, is a privacy violation and is bound to cause expensive false alarms, on top of not once (at least to my knowledge) actually preventing an attack. This is literally a case where they got it wrong, 100k was spent for no reason and some guy is currently under trial for shitposting on a private messaging group. The fighter jet pilots had to subjectively judge the situation and decided there was no real threat; imagine if the pilot had made a mistake and the fighters mistook it for an attempt at dive bombing something, then shot down the passenger plane? The idea that there's no subjective judgment at play here is ridiculous. Do we send a paramedics team out every time some teenager goes "haha I can't I'm literally gonna kms dude lmao" in their group chat? Some followup is certainly warranted in this case but immediately assuming it's a fully serious bomb threat is not.

You can read the ELF header of the executable at runtime https://stackoverflow.com/a/34960487 Honestly this whole thing looks like more work than it's worth. Why do you even need to know which optimization level was used at runtime?

Or you could carry a bomb into a crowded train station and do the same if not more damage. There's no security to intercept you at any point there. I wonder why we're ok with that risk but even a single intercepted text message is enough to scramble everyone and their dog when a plane is involved. Regardless, I don't think it's at all reasonable to expect this guy would know his message could cause this reaction, so even if it is deemed necessary then it's just the cost of doing business this way.

It's a long chain of unlikely hypotheticals that I don't think the teenager in question can be held responsible for. I must stress that no terror attack has ever been prevented this way.

Again not something fighter jets can stop... As I explained this is just excessive precaution. Terrorist acts can be performed outside of airports and yet in daily life no such precautions are taken. The one thing that makes planes special is that they can be hijacked and used to, say, ram skyscrapers; this is now impossible because the pilot's cabin cannot be opened from the outside on modern planes. Airports already have, by far, the highest security level of any form of transport and the chances of you making it to a plane with explosives is extremely low; it's much easier and equally (or more) effective to stage the attack in the airport itself at that point. So yes, they can just take the risk and they do in virtually every other situation. Terror attacks are often prevented through normal investigative methods, not by randomly intercepting a single snapchat message where a teenager writes "gonna blow up the plane lmao". And that one was a scandal because it's not supposed to do that. A random terrorist wouldn't know that when not even the pilots did. If a pilot is involved you don't need an explosive to hijack the plane...

If they scrambled jet interceptors every time anyone says anything that might be considered threatening, despite no prior history of doing anything wrong and no other signs of it being a serious threat, then you'd have them in the air 24/7. The attack that caused airport security to be the way it is was carried out by people who were already known to law enforcement and could (and should) have been stopped upon checking their documents; cases of people getting through modern airport security and carrying out any kind of attack currently sit squarely at 0 as far as I know. Also I'm curious what fighter jets are supposed to do about a passenger trying to blow up the plane. If anything they're more likely to cause someone with a bomb to panic and decide to just do it. You can't even enter pilot cabins from the outside anymore so something like the WTC attack is just not possible; at worst you have a hostage situation, which again is not helped by jet fighters. Meanwhile anyone can just walk on a train and blow it up with nothing stopping them. You tell me if this makes any sense to you. Yeah, if you shout it out at the airport, of course, you're causing public distress and panic. Not so with a text chat. If it's an in depth investigation then yes, chat logs can be used as indicators and possibly evidence in a trial, but it's never a single message immediately triggering a full force response... at most I could have seen him be briefly detained on arrival.

Not if you do it in public in a way that affects others around you... but that hardly applies to a supposedly private chat. Oh please, they spied on this guy well enough to figure out His name The plane he was on Private messages between him and his friends but they just couldn't wrap their minds around him just being a teenager..? Apparently he's a somewhat known chess player too, so a 1 minute internet search would have pretty much ruled out the possibility of him being serious. Not to mention you can't board a plane without going through multiple security scans. What are those for if not to identify actual potential threats? I'll tell you what happened here; they saw his skin color in the picture and their critical thinking went out the window. Either that or massive incompetence. He thought his chat was private so they can't accuse him of creating disturbance on purpose either.

From The Times: Yeah, it's sounding less believable by the minute... or at least unsubstantiated. I do wonder whether snapchat uses HTTPS... either way it seems more likely snapchat picked it up on their end and notified authorities.

End to end encryption is designed precisely to make this impossible. That's also possible... the article only says it was "assumed" the message was read through the wifi network: Also worth noting that the network being open or not is pretty much irrelevant if airport security has control of it. Also yeah spain doesn't have a leg to stand on to get reimbursed for the jets as far as I'm concerned, it's not illegal to joke and there is no law (at least afaik) that makes it illegal on airport grounds either. It's one thing if he shouted "BOMB!" for everyone to hear, but he had no way of knowing anyone but his friends would read this.

Text messages on snapchat are not encrypted: https://www.telegraph.co.uk/technology/2019/01/09/snapchat-adds-end-to-end-encryption-protect-users-messages/

as I said: in gcc there is also this: https://stackoverflow.com/a/12112479

Optimization level is an abstraction of a series of compiler options which could be used individually so I can see why there wouldn't be a special predefined macro for it; it might even change which exact flags are enabled depending on the compiler version. If you want to keep track of this (although I struggle to see a use case) you could manually define a preprocessor variable using the -D flag (in GCC): gcc -O3 -Doptimization_level=3 [...] then in your code: #ifdef optimization_level const char OPT_LEVEL = optimization_level #else const char OPT_LEVEL = 0 #endif this way at runtime you could check the value of OPT_LEVEL to find out which optimization level was used... assuming you passed the right value. This can be automated with something like cmake. Alternatively you could define a string containing all compiler options.

Certainly, the promised speeds and throughput would not be achievable without maglev. At most you might be able to claim power savings on roughly the same speed and throughput due to reduced air resistance (depending on how much power the vacuum pumps would need). And then the trains would need to be airtight as well... it's just a shitshow all around for almost no benefit. But I still take issue with people here pretending something like this would be remotely close to the original concept just to win the argument for daddy Elon. And yeah, I hadn't even thought about how the heck they would cool the whole thing with a reduced atmosphere, especially in an underground tunnel.

To me the main disadvantage is incompatibility with some broadly used software and some poor driver ports, especially for GPUs.

No, you're the one failing at the most basic math. The costs of maglev, with or without a vacuum tube, are two or three orders of magnitude higher than standard rail and would easily double or triple the cost of that $1 billion 20km line by changing nothing other than the railway itself. That's because standard rail is cheap. Using maglev would make the cost of the rail tower over everything else in the project. It's like saying the cost of a GPU is a small part of the cost of a $500 laptop with an iGPU and therefore adding a $2000 RTX 4090 would not increase it significantly. I have already isolated the variable we should be looking at and the costs are obviously and unjustifiably much higher, for little or no gain in the context given. You've provided no numbers on hyperloop other than "trust me bro it's not that expensive". I don't see the point of discussing this further if you refuse to understand a concept a 10 year old would have no trouble with. Yes, because that was the definition of the concept. If hyperloop was going to build a normal railway in a vacuum tube they could have bloody well said so and maybe tried to actually build it. You don't get to completely change the parameters of the project and then act as though the original proposal made any sense. I am not considering the use of standard rail because that's not what was on the table. If your argument relies on this being done with standard rail then I have no interest in the conversation, it's not what I've been talking about at any point. Plus, the whole premise of this being an alternative to the supposedly poorly handled california HSR would kind of fall apart if you were going to build it anyway and just add a vacuum tube, wouldn't it? EVs are another beast entirely but do consider that in practical terms, were it not for the environmental impact, ICE vehicles still give EVs a run for their money in many ways. The hyperloop can't seriously claim it's better for the environment than standard electric HSR. Also while EVs are generally more expensive than ICEs (although as mentioned by @Kisai this is more of a market problem than a technical inevitability) they are certainly not multiple orders of magnitude more expensive.

I don't expect the cramming and "nickel and dime"ing to be any lower on a system that needs to pay back such insanely expensive infrastructure. Airport security does suck but it's more of a political problem than anything inherent to the technology. There have also been advancements in security scanner technology that make it less annoying, for example in some airports you can now take bottles of liquids with you and you don't need to take your belt off. I don't think that's supposed to be a full size train in the picture. It looks like an unmanned test pod. The tunnel is likely only 2-2.5m wide if that track is the width of a normal maglev track.

Why would the mass be "much" lower? I already wrote that the upper bound cost for high speed double track rail is 165k. Pennies compared to any form of maglev. Underground. Keyword is under. I don't think you want to get into the costs of digging out all of this to have it underground, we're already at orders of magnitude higher cost than regular rail. Or have it elevated for similar reasons. Also if the city has a subway it cuts down the time to reach the airport to something like 30 minutes from the center of a city like paris. You guys keep violating the original premise of your examples as soon as I point out that it would still be insanely expensive for little gain without realizing that variations would also significantly add to the cost or make it even less practical to build. Yes, most railway stations are in city centres. They don't require huge straight tubes though and, generally, in cities as large as paris there are additonal ways to move around quickly using public transport, which negate some of the accessibility advantage compared to airports. Also you're ignoring the point about how this would never get sufficient traffic to pay off the construction costs. Planes don't require building tracks to reach their destination.

300 kph is achievable with normal high speed rail. You couldn't have a giant tube cutting through a city center either for that matter, and the lack of intermediate stops (absolutely essential if you want to maintain those speeds) would make it about as difficult to access as an airport if you don't live in the few "chosen" locations for a stop. I mean, if you live on the outskirts of Istanbul do you think you'd have an easier time reaching the hyperloop station in the city center as opposed to the airport? All these considerations just assume that hyperloop would somehow be able to magically ignore all the reasons high speed rail isn't ubiquitous like right of way on large stretches of currently private land... Oh I absolutely disagree. I also doubt enough people need to go from berlin to frankfurt daily that the cost would be justified.

No, the argument is not "higher cost = bad". Extreme cost for something that isn't worth it is bad, is the argument - and the inevitable attempt to cut costs resulting in the thing not working, or being dangerous, or significantly cutting back on features as has been the case with the Las Vegas loop. Cars can be made cost effectively, they are a solved engineering problem (although there's always room for improvement). Making the hyperloop cost effective would be impossible. We're having this discussion over the corpse of the company that attempted it for a decade and has nothing to show for it. Those lines are expensive for a reason, and that reason is not that standard rail is somehow comparably expensive to maglev in those projects. They likely have to route it through inhabited areas, acquire land, obtain grants, run simulations and go through bureaucracy - that's what makes them expensive. A hyperloop would be no different in this regard. Those are costs on top of the cost of the system itself. Yeah, and do you think you could fill a train every two minutes of people like that who need to get across california? What about normal people, do they not have a right to a sanely priced form of high speed transport? Computers were built to, are excellent at and are still used to crunch numbers. Everything they are able to do today is just them crunching numbers really fast. Here we're talking about a form of public transport that's bad at public transport... and would have no other uses. That's a ridiculously terrible example because 1) as I mentioned just because it's an expensive railway doesn't mean a hyperloop wouldn't be subject to the same extra costs and 2) 20km of urban railway have absolutely no need to go faster than like 100kph, which would mean going the entire distance in 5 minutes. It's arguably the worst example you could make of a use case for a 600kph train. Except we conveniently have no total cost for a hyperloop project because none were made (because it's a bad idea that was never going to work). We only have a napkin math estimate from the snake oil salesman who pitched it that we know is complete horseshit because it wouldn't even cover the pure track cost for 100km of maglev. Why would you just assume that? 1 billion is just the track cost for 10km of maglev vs less than two million for the same length of conventional high speed rail. You'd be (at a minimum) almost tripling the overall cost for a project that has no need for a higher speed. Of course if the cost difference for the rail were like 10% more this wouldn't be an issue (although again there really wouldn't be any reason to do that since low speed trains are perfectly adequate for the task), but we're talking literally 100 times the cost. I'm telling you, with numbers at hand, that it would have an enormous impact on the cost of any project while not solving any of the issues that actually make projects like the canada line and the california HSR expensive and difficult in the first place.

To elaborate, the likely reason this happens is that the operating system may schedule execution of other processes in the middle of your strlen call, varying the time required. Generally tests like this are more relevant over thousands or millions of executions where you might see a relevant change in the average time. As pointed out by others @Gat Pelsinger, never assume you're smarter than the compiler unless you've analyzed the resulting binary. Also, "int" is not the same size on all systems. using size_t makes it so that the function will work on any system, on strings as long as the system allows. Your code also declares a new variable (i) for that matter. On any decent compiler, a for loop and a while loop doing the same thing will result in the same exact binary. It's just syntactic sugar. As mentioned this all gets optimized away by the compiler but, if it weren't, consider that every time you use str[i] you're doing an addition.

I wouldn't be so sure once you consider the costs of a stable, a carriage and someone who takes care of the horse every day. Regardless, even at face value the cost of a car is generally low enough that people can afford to buy one (although that's been changing recently...) and the advantages compared to the horse are so many that even a 10x cost would be justifiable. Here on the other hand we're talking about potentially spending hundreds of times more for a single potential benefit in the form of higher maximum speed... and not even that much higher in relative terms. A higher speed wouldn't even necessarily translate into a proportionally higher throughput if the trains would need to be shorter and less spacious. By the way I like the "logic" here... I guess if spending more for higher speed in one instance is worth it then it must always be worth it...? I imagine you'd also argue that having everyone fly on a private jet for their daily commute would also be well worth the price in exchange for going 900kph? I'm considering the use case it was proposed for. I struggle to see any use case for which it would be an economically viable alternative to rail, but even if there is one I don't really care; it was supposed to be built to do one thing and I'll critique it based on its inadequacy for that. I already posted and sourced the cost of laying double track high speed rail to be 165k/km. This is just for the physical rail, not other things that are independent of the type of rail used and would be present in the hyperloop as well and should therefore not be counted in a comparison. It's a 100x to 1000x lower price than maglev rail, not even accounting for the tube/tunnel. That's already 10x the price of a railway, just for the tube.